Many of the criticisms I've seen of Halo 4 are from reviewers with the expectations that the game should be something else. Whatever their expectations, it isn't based on the history of the franchise's narrative or gameplay or linearity. Halo 4 isn't going to be something different than previous iterations. No game is. What it is, is the best of what the franchise has always done, in a polished packaged, iterated to almost perfection. Let the game be what it is!